lO 



Plants and their Ways in South Africa 



there is another food storing region (perisperm). It can be 

 seen plainly in young seeds, and its position will remind you of 

 the thin layer in the pine seed.' 



Examine a date and compare the seed with that of 

 Hcemantiius. 



" Water Uintjes " {Aponogeton) has one large green coty- 

 ledon, a thin plumule, and a very small radicle. 

 Its food is all stored in the cotyledon. 



Plants which have two cotyledons are called 

 Dicotyledons, those with only one are Mono- 

 cotyledons. It is an important distinction. 

 Most monocotyledons have endosperm. " Water 

 Uintjes " [Aponogeton) is an exception. The 

 plants in each group have other characters in 

 common which we shall find out later. 



In HcEmanthus and date the embrjos are so 

 very small that the food supply seems unneces- 

 ^Seed sarily generous ; but it takes a long while for the 

 date to get a firm footing in the soil, and the 

 "April Fool" is always liable to be overtaken by 

 drought. Nature provides for her children gener- 

 ously, and we all know, when it comes to a ques- 

 tion of food, it is better to have too much than 

 not enough. 



By this time we have' examined enough seeds to find 

 evidence of provision for the future of the little plants, and as 

 we follow their histories we shall find other conditions admir- 

 ably fitting them for their struggle in life. 



Fig 

 of "Water 

 Uintjes" (Ap- 

 onogeton). I, 

 large fl e s h y 

 cotyledon ; 2, 

 plumule; 3, 

 small radicle. 



How Seedlings Beh.we when they ^Vake Up. 



Zea Mays comes up Head Foremost. — Vou may mis- 

 take the little pointed object for a stem, but in a few days you 



' Perisperm is usually consumed as the seed develops. Strelitzia 

 and iMesembi'iaiitlicmiuii may be mentioned as seeds in which it persists 

 in the ripened seeds. In the pine, only a small part of the thin layer inside 

 the seed-coat is perisperm, the remainder is the inner part of the testa 

 which splits away in the ripe seed. 



